Enclosed water turbine power generation

[Dshaff]

TL;DR

Question for all the smart folks out here. Ive been thinking about creating a fully enclosed power generation system for a home. The idea is to hook up a water pump (say 90gpm flow) run pvc up and then back down to a water turbine, with the exiting water going directly back to the pump. In essence the thought would be to constantly create power to a home. The question is this: is this feasible, and if so why isn't everybody doing it?

In theory or at least in my head, it seems simple enough to me. A simple water pump, such as a pool pump pushes water through a pipe into a water turbine and recycles the water directly back to the pump. With some of the hydrogenerators I've seen out there, they produce far more power than the pump would use creating the additional free power to run a home. Surely i can't be the first person to think of this, so what's the flaw? It seems like something like this could be scalable to many sizes and electrical outputs, for me I am just thinking about running a home and a shop.

 

[berkeman]

Welcome to the PF.

What you are describing is a classic Perpetual Motion Machine (PMM). We don't discuss or debunk them here on the PF, since they are already addressed well by many other websites. Here are some links for your reading pleasure. This thread is closed.

Perpetual motion and "free energy" discussions
http://en.wikipedia.org/wiki/Perpetual_motion
http://www.skepdic.com/freeenergy.html
http://www.skepdic.com/perpetual.html